The 11.1-RC3 can only boot and attach disks in "Safe mode", otherwise gets stuck attaching

[Mark Johnston]

On Tue, Jul 18, 2017 at 01:01:16AM +0200, Mark Martinec wrote:
> Upgrading 11.0-RELEASE-p11 to 11.1-RC3 using the usual freebsd-update 
> upgrade
> method I ended up with a system which gets stuck while trying to attach
> the second set of disks. This happened already after the first phase of
> the upgrade procedure (installing and re-booting with a new kernel).
> 
> The first set of disks (ada0 .. ada2) are attached successfully, also a
> cd0, but then when the first of the set of four (a regular spinning 
> disk)
> on an LSI controller is to be attached, the boot procedure just gets
> stuck there:
> 
>    kernel: ada1: 300.000MB/s transfers (SATA 2.x, PIO4, PIO 8192bytes)
>    kernel: ada1: Command Queueing enabled
>    kernel: ada1: 305245MB (625142448 512 byte sectors)
>    kernel: ada2 at ahcich6 bus 0 scbus8 target 0 lun 0
>    kernel: ada2: <OCZ-VERTEX3 2.25> ATA8-ACS SATA 3.x device
>    kernel: ada2: Serial Number OCZ-O1L6RF591R09Z5C8
>    kernel: ada2: 300.000MB/s transfers (SATA 2.x, PIO4, PIO 8192bytes)
>    kernel: ada2: Command Queueing enabled
>    kernel: ada2: 114473MB (234441648 512 byte sectors)
>    kernel: ada2: quirks=0x1<4K>
>    kernel: da0 at mps0 bus 0 scbus0 target 2 lun 0
> 
> (stuck here, keyboard not responding, fans rising their pitch,
>   presumably CPU is spinning)

Are you able to break into the debugger at this point? Try setting
debug.kdb.break_to_debugger=1 and debug.kdb.alt_break_to_debugger=1 at
the loader prompt, and hit the break key, or the key sequence
<CR> ~ ctrl-b once the hang occurs. At the debugger prompt, try
"bt" and "show allpcpu" to start.